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Solar-reflective ramada helps cool local dog park

June 9, 2023

RJ Dog Park in Phoenix just got a little cooler. It is now home to Arizona’s first “Passive Daytime Radiative Cooling Ramada,” a unique solar-reflective ramada built by Arizona State University researchers to better understand the role “cool" surfaces can play in improving the comfort of people — and their four-legged friends — in public spaces.

Find out how it works

City of Tempe, ASU partner on 'Jenny’s Trailer' to provide space for homeless individuals to cool off during summer

June 30, 2022

Check out one of HUE's latest collaborations with the City of Tempe! Jenny’s Trailer is a new, solar-paneled mobile cooling center built in partnership with Tempe’s Homeless Outreach Prevention Effort (HOPE) that serves as a place of shelter during extreme heat. The HOPE team travels around city parks and other locations weekly to provide the homeless a place to cool off and receive cold bottled water, as well as offer housing and social services provided by Tempe. Check out more details here!

Heat Ready Schools program aims to keep kids safe on campus

June 1, 2022

HeatReady Schools, a HUE-funded pilot project led by Jenni Vanos, discusses their collaboration with Phoenix schools, including Paideia Academies, that aims to mitigate heat risk by helping schools create a safer environment for their students. As part of this effort, a HeatReady Scorecard was created, which includes a set of 30 recommendations for what makes a heat-ready school. The scorecard is designed to help school administrators gauge their school’s heat preparedness, and find areas for improvement. As the program grows, developers hope to create an official Heat Ready certification that schools can earn.

Check it out on ABC 15!

South Phoenix streets get reflective coating to reduce excessive heat

October 27, 2021

The second phase of Phoenix’s Cool Pavement Program in south

Phoenix has kicked off. The Office of Heat Response and Mitigation is part of this effort, with $2.8 million allocated for its creation. The city also plans to continue to budget for its Tree and Shade Master Plan, which will bring 30 “cool corridors” to underserved communities by 2050. Cool corridors are mile-long stretches of up to 200 trees or shade structures.

Read the full article on AZ Central. 

Image: A truck prepares to coat the asphalt near Roesley Park in south Phoenix with a water-based reflective coating as part of Phoenix's Cool Pavement Program. Early findings show the treated asphalt is 10 to 12 degrees cooler than traditional asphalt. Photo credit: Megan Taros/The Republic

City of Phoenix adopted the 2021 Climate Action Plan

October 21, 2021

Phoenix Mayor Kate Gallego and the City Council have adopted a Climate Action Plan roadmap to cut emissions and build a more resilient city by approving the City’s comprehensive action plan to reach its net-zero goal a decade or earlier. HUE celebrates this milestone and is excited to continue collaborating with the City of Phoenix to implement specific actions.

Read story here.

View the plan.

Phoenix names a heat officer, with a goal of easing the risk of rising temperatures

October 12, 2021

Phoenix Mayor, Kate Gallego, introduced new heat mitigation officer, David Hondula, outside City Hall. Photo from, taken by Brandon Loomis

"Phoenix has appointed one of the leading experts on urban heat to run a program the city hopes will save lives and reduce urban temperatures even as climate change warms the surrounding desert.

Mayor Kate Gallego on Wednesday introduced David Hondula as director of the nation’s first publicly funded office of heat response and mitigation. The longtime Arizona State University environmental scientist and heat researcher will retain a post at the school but work full-time coordinating heat-reduction strategies."

Read the full story here on AZ Central

HUE partnership with City of Tempe for mobile cooling trailer looks forward to future

September 29, 2021

HUE and the City of Tempe unveiled a new project that will not only serve as a place of shelter from the brutal summer heat in the Valley of the Sun, but offer a place for the unhoused community to connect to resources. The mobile cooling trailer was made possible through the generous donation of local philanthropists, Jenny Norton and Bob Ramsey, and will be staffed by the city’s Homeless Outreach Prevention Effort (HOPE) team. 

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Extreme Heat and Public Health Podcast

August 23, 2021

Jennifer Vanos, a HUE partner and Assistant Professor at the School of Sustainability, College of Global Futures, and Rachel Braun, a Postdoctoral Research Associate with HUE, have been featured in Come Rain or Shine podcast produced by the SW Climate Adaptation Science Center (SW CASC) and the USDA Southwest Climate Hub to talk about the impacts of extreme heat on public health, especially on vulnerable groups.

Listen to the podcast here!

Silent killer: The rising problem of extreme heat in the U.S.

July 23, 2021

Congratulations to Melissa Guardaro, PhD, a HUE member, Knowledge Exchange for Resilience and Assistant Research Professor at the Global Institute of Sustainability and Innovation, for testifying in front of the U.S. House of Representatives Committee on Science, Space, and Technology hearing on the rising problem of extreme heat in the U.S.

U.S. House Testimony

How America’s Hottest City is Innovating to Survive | Weathered

July 6, 2021

Phoenix heat was the topic of discussion in the latest episode of PBS' 'Weathered', a show that helps explain the most common natural disasters, what causes them, how they’re changing, and what we can do to prepare. This episode features ASU researchers and HUE affiliates Mikhail Chester, Ariane Middel and David Hondula.

"Perhaps no place in the United States more clearly illustrates the dangers of global warming than Phoenix, Arizona. 2020 was their hottest year on record, with 53 days reaching at least 110 degrees F. And heat-related deaths there have more than doubled over the last 5 years. But while these trends are truly disturbing, there is hope. Because of its extreme circumstances, Phoenix has been forced to explore innovative solutions and is learning how to adapt urban life to hotter and hotter temperatures.

In this episode of Weathered, we delve into the latest science of the “urban heat island” effect, learn about the looming threat of a potential “Katina-like event” that threatens their electrical grid, and explore the gamut of options being pursued by scientists and activists to make life safer and more livable in America’s hottest city."

A Double Heat and Housing Crisis in Phoenix

June 23, 2021

construction crew working in the heatIn the June 20 edition of The New York Times, writer Jack Healy visits Phoenix to explore how the region is addressing a housing shortage while in the midst of near-record heat. The article interviews Melissa Guardaro, an assistant research professor at the Global Institute of Sustainability and Innovation at Arizona State University and a HUE researcher.

“Extreme heat has made the problems we have all the more evident,” said Melissa Guardaro, regarding the rising housing crisis and the scorching heat in Phoenix.

Read the full article. ASU faculty, staff and students can read the article with a free New York Times group pass subscription via ASU Libraries.

Do trees provide the best shade for urban environments?

June 9, 2021

Shade monitoring at ASU ariane middelShade is a term that residents of arid, hot environments learn to appreciate, especially during scalding summer months. But what makes for the best shade?

“Cities have started to plant trees as a means to shade the environment. But oftentimes you can’t really plant trees because of infrastructure challenges. There may be sewer lines underground, internet cables, or business signs that will be blocked,” said sustainability scientist Ariane Middel, assistant professor in ASU’s School of Arts, Media and Engineering and a HUE grantee. New research explores viable alternatives to trees for providing shade to keep people comfortable outdoors.

Using a special mobile lab named MaRTy, Middel and her team are assessing what makes for the best provider of shade. The findings may surprise you.

Learn more at ASU News.

2020 brings record heat and dryness to Arizona

February 12, 2021

“The heat in 2020 was not helpful in the least, and the global pandemic was not helpful as well,” said associate professor David Hondula, a partner with the Healthy Urban Environments program at the Global Institute of Sustainability and Innovation.

In an article featured in the Arizona Republic, Hondula points to energy assistance and home weatherization assistance for low-income people as solutions to help avoid severe risk and even deaths due to the extreme heat and conditions of the current climate.

Read more about the consequences of the State’s driest summer on record and the pandemic on vulnerable people in our communities.

Transforming Phoenix into an 'urban forest' to combat extreme heat

The State Press | October 15, 2020

two people dig holes to plant trees in city parkA State Press article detailed how the Healthy Urban Environments Initiative partners are working with Phoenix city officials to reduce temperatures across the Valley after a record-breaking summer.

Reducing temperatures for low-income communities and other efforts to make Phoenix a "HeatReady" city were among the topics discussed at the latest Urban Heat Island/Tree and Shade subcommittee meeting. "The closing of cooling areas was a move that largely affects the most vulnerable people who can't afford air conditioning, according to Charles Redman, a professor at the School of Human Evolution and Social Change, who said that heat is a 'real public threat.'"

Read more in the article, "Transforming Phoenix into an 'urban forest' to combat extreme heat."

Cool pavement pilot study

September 4, 2020

Woman on ASU Tempe campus operating weather robotThe City of Phoenix Street Transportation Department recently initiated the Cool Pavement Pilot Program. With this project, the city plans to apply the product CoolSeal by GuardTop®, which is a water-based asphalt emulsion seal coat designed to achieve lower pavement surface temperatures through its lighter color and reflectivity.

A joint study between Arizona State University researchers — led by Ariane Middel and Jenni Vanos — and the City of Phoenix, and sponsored by the Healthy Urban Environments Initiative, will quantify and evaluate the effectiveness of the CoolSeal product in mitigating urban heat considering various heat metrics (air temperature, surface temperature and radiant temperature). This one-year project will also assess the product performance and life cycle.

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AZ Heat Preparedness and Resilience Workgroup

August 21, 2020

Downtown Phoenix skyline with yellow skyThis Workgroup was created in the summer of 2020 to share heat forecasts and warnings with communities; highlight approaches to heat relief, communications strategies and resources; identify opportunities and gaps in heat-related research; and connect cities and counties to regional and state resources and information. Read more on the Workgroup's webpage.


Healthy Urban Environments (HUE)

Knowledge Exchange for Resilience (KER)

Sustainable Cities Network (SCN)


  • Melissa Guardaro, Assistant Research Professor, ASU Julie Ann Wrigley Institute of Sustainability; Healthy Urban Environments (HUE) & Knowledge Exchange for Resilience (KER)
  • Liza Kurtz, ASU PhD Student, Global Health
  • Anne Reichman, Director, ASU SCN & Project Cities
  • David Hondula, Associate Professor, ASU School of Sciences and Urban Planning
  • Paul Iniguez, Science & Operations Officer, NOAA/National Weather Service Phoenix, AZ
  • Braden Kay, Sustainability Director, City of Tempe

graph of heat related deaths in Arizona
Source: Arizona Department of Health Services

Event Sept. 3: Killer Heat in COVID Times

August 14, 2020

paris-climate-agreement-asuLast month, Phoenix broke its record for the most days at 110-plus degrees, while being the world's hotspot for coronavirus. This case critical discussion brings together ASU, the City of Phoenix, as well as a local nonprofit and a national NGO, to discuss the compounding crises of extreme heat and COVID-19.

Sustainability scientist Ariane Middel advances the field of urban climate science in her work with ASU’s HUE initiative. Juan Declet-Barreto is a contributing author of Killer Heat in the US and a blog that analyzed the compounding crises of extreme heat and COVID-19. Mark Hartman, from the City of Phoenix, is working with ASU’s HUE project to understand and mitigate extreme heat in Phoenix. Masavi Parea represents CHISPA, a community-organizing program advocating for resilience and climate justice in Phoenix.

Co-hosted by ASU's HUE (Healthy Urban Environment) initiative.

Register via Zoom

2020 HUE Recipients

July 31, 2020

city with mountains in distance and street in foregroundHealthy Urban Environments' second convening, on July 29, focused on the 2020 cohort who are just starting their projects during COVID-19. With 38 participants in attendance each team presented their progress as well as the challenges and adjustments each project had to endure.

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With the help of ASU, city of Phoenix developing solutions to cool down

The Washington Post | July 10, 2020

Phoenix skyline at sunsetDavid Hondula, a senior sustainability scientist in the Julie Ann Wrigley Global Institute of Sustainability, was interviewed by the Washington Post about the Heat Ready initiative, a project funded by Healthy Urban Environments.

“We talk about climate … as something mysterious and ambiguous that comes from the sky. But it is also something we are driving with the way we are paving our streets,” Hondula said in the article. “Urbanization is a critical part of the story.”

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